In recent years, thin and lightweight notebook computers as well as large screen TVs have increasingly been developed. Along with the above, a decrease in thickness, an increase in size, and higher performance have increasingly been sought for polarizing plate protective films employed in display devices such as a liquid crystal display device. Of these, heretofore, liquid crystal display devices have had a problem of narrow view angle. In order to increase the view angle of liquid crystal display devices, a method is proposed in which an optical compensating resin film is employed (refer, for example, to Patent Document 1).
Further, employed in current polarizing plates is a cellulose ester film as a protective film, which has a problem in which its retardation value reversibly varies depending on humidity. Consequently, it is proposed that the above variation is reduced by changing plasticizers and regulating film thickness (refer, for example, to Patent Document 2).
Further, display changes due to the view angle, especially color changes, have caused problems, whereby improvements have been proposed in which rodlike compounds are newly introduced (refer, for example, to Patent Documents 3 and 4).
By employing the above means, it is possible to reduce display changes and color variation, however its level of contrast has still been insufficient. Consequently, technical means to overcome this drawback have been sought.    Patent Document 1: Japanese Patent Publication Open to Public Inspection (hereinafter referred to as JP-A) No. 6-222213    Patent Document 2: Japanese Patent Application No. 2005-161095    Patent Document 3: JP-A No. 2002-267847    Patent Document 4: JP-A No. 2004-4550